Lewis 1999.

Methods	A single‐centre unmasked randomised controlled trial conducted during a 36‐month period.
Participants	135 women with a diagnosis of PPROM ≤ 34 + 0 weeks' gestation at Louisiana State University School of Medicine, Shreveport, Louisiana, USA, and who were stable after 24 hours' monitoring. 66 (66 available for analysis) women were randomised to the biophysical profile group and 69 (69 available for analysis) women were randomised to the nonstress test group.
Interventions	Daily nonstress test versus daily modified biophysical profile.
Outcomes	Latency period (days from rupture of membranes to birth). Days from birth to discharge home. Birthweight. Neonatal antibiotic use (days). Respiratory distress syndrome. Intraventricular haemorrhage. Necrotising enterocolitis. Bronchopulmonary dysplasia (interpreted in our review as oxygen treatment after 36 + 0 weeks). Retinopathy of prematurity. Intra‐amniotic infection (maternal chorioamnionitis) (diagnosed by analysis of amniotic fluid obtained from an amniocentesis or by a maternal temperature of 100.4°F, foul smelling fluid, and uterine tenderness). Maternal endometritis. Neonatal sepsis. Presumed neonatal sepsis (diagnosed when there were clinical signs of infection with negative culture results and an abnormal leukocyte count). Neonatal pneumonia (diagnosed by a positive radiographic finding plus evidence of sepsis). Corticosteroid use. Delivery for maturity. Caesarean delivery. Apgar score of 7 or less at 5 minutes.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation	Low risk	Random number tables with a 1:1 match were used to generate allocation sequences.
Allocation concealment	Low risk	Allocation cards were kept in opaque envelopes and not opened until after informed consent was obtained.
Blinding (participants and personnel)	High risk	The nature of the intervention prohibited participant or clinician blinding.
Blinding (outcome assessment)	Unclear risk	Outcome assessor blinding is not described, therefore the risk of bias arising from this is unclear.
Incomplete outcome data addressed All outcomes	Low risk	No loss of participants to follow‐up at each data collection point. No exclusion of participants after randomisation.
Free of selective reporting	Low risk	There is no suggestion of selective reporting of outcomes. All main outcomes described in the methods are reported in the results.
Free of other bias	Unclear risk	The number of women with multiple gestations is not reported. These women were not excluded from the study, but a subgroup analysis of their effect has not been described. Therefore the risk of bias arising from the inclusion of women with multiple gestations in the analyses is unclear.

PPROM: preterm prelabour rupture of membranes